2JOF

The Trp-cage: Optimizing the Stability of a Globular Miniprotein

2JOF の概要

• エントリーDOI: 10.2210/pdb2jof/pdb
• 関連するPDBエントリー: 1jrj 1l2y
• NMR情報: BMRB: 15169
• 分子名称: TRP-CAGE (1 entity in total)
• 機能のキーワード: de novo protein, miniprotein, two-state folding, trp-cage
• 由来する生物種: synthetic construct
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 2088.24

構造登録者

Barua, B.,Andersen, N.H. (登録日: 2007-03-09, 公開日: 2008-03-04, 最終更新日: 2024-05-08)

主引用文献

Barua, B.,Lin, J.C.,Williams, V.D.,Kummler, P.,Neidigh, J.W.,Andersen, N.H.
The Trp-cage: optimizing the stability of a globular miniprotein
Protein Eng.Des.Sel., 21:171-185, 2008

PubMed Abstract: The Trp-cage, as the smallest miniprotein, remains the subject of numerous computational and experimental studies of protein folding dynamics and pathways. The original Trp-cage (NLYIQWLKDGGPSSGRPPPS, Tm = 42 degrees C) can be significantly stabilized by mutations; melting points as high as 64 degrees C are reported. In helical portions of the structure, each allowed replacement of Leu, Ile, Lys or Ser residues by Ala results in a 1.5 (+/-0.35) kJ/mol fold stabilization. No changes in structure or fluxionality of the core results upon stabilization. Contrary to the initial hypothesis, specific Pro/Trp interactions are not essential for core formation. The entropic advantage of Pro versus Ala (DeltaDeltaS(U) = 11 +/- 2 J/mol K) was measured at the solvent-exposed P17 site. Pro-Ala mutations at two of the three prolines (P12 and P18) that encage the indole ring result in less fold destabilization (2.3-3.4 kJ/mol). However, a P19A mutation reduces fold stability by 16 kJ/mol reflecting a favorable Y3/P19 interaction as well as Trp burial. The Y3/P19 hydrophobic staple interaction defines the folding motif as an 18-residue unit. Other stabilizing features that have been identified include a solvent-exposed Arg/Asp salt bridge (3.4-6 kJ/mol) and a buried H-bonded Ser side chain ( approximately 10 kJ/mol).

PubMed: 18203802
DOI: 10.1093/protein/gzm082

実験手法

SOLUTION NMR